Matlab工厂模式

工厂模式定义一个用于创建对象的接口，让子类决定实例化哪一个类，工厂方法使一个类的实例化延迟到其子类。工厂模式主要分为简单工厂模式、工厂方法模式以及抽象工厂模式。

obj.m

classdef obj < handle
    methods
        function desc(~)
        end
    end
end

object1.m

classdef object1 < obj
    methods
        function desc(~)
            disp('this is object1 class');
        end
    end   
end

object2.m

classdef object2 < obj
   methods
        function desc(~)
            disp('this is object2 class');
        end
    end   
end

简单工厂模式：

simplefactory.m

classdef simplefactory   
    methods
        function res = createobject(~,obj_name)
            if  strcmp(obj_name,'object1')
                res = object1();
            elseif strcmp(obj_name,'object2')
                res = object2();
            else
                res = object.empty();
            end
        end
        function res = createobjecteval(~,obj_name)
            res = eval(obj_name);
        end
        function res = createobjectstr2func(~,obj_name)
            conshandle = str2func(obj_name);
            res = conshandle();
        end
        function res = createobject1(~)
            res = object1();
        end
        function res = createobject2(~)
            res = object2();
        end
    end
    methods(static)
        function res = createobjectstatic(obj_name)
            if  strcmp(obj_name,'object1')
                res = object1();
            elseif strcmp(obj_name,'object2')
                res = object2();
            else
                res = object.empty();
            end
        end
    end
end

测试代码：

%简单工厂模式
fac = simplefactory();
obj1 = fac.createobject('object1');
obj1.desc();
obj2 = fac.createobject('object2');
obj2.desc();
 
%通过eval函数
fac = simplefactory();
obj1 = fac.createobjecteval('object1');
obj1.desc();
obj2 = fac.createobjecteval('object2');
obj2.desc();
 
%通过str2func函数
fac = simplefactory();
obj1 = fac.createobjectstr2func('object1');
obj1.desc();
obj2 = fac.createobjectstr2func('object2');
obj2.desc();
 
%静态工厂模式
obj1 = simplefactory.createobjectstatic('object1');
obj1.desc();
obj2 = simplefactory.createobjectstatic('object2');
obj2.desc();

%多方法工厂模式
fac = simplefactory();
obj1 = fac.createobject1();
obj1.desc();
obj2 = fac.createobject2();
obj2.desc();

工厂方法模式：

methodfactory.m

classdef methodfactory   
    methods(abstract)
        factorymethod(~);
    end
    methods
        function dosomething(obj)
            disp('this is method factory!')
            o = obj.factorymethod();
            o.desc();
        end
    end
end

methodfactory1.m

classdef methodfactory1 < methodfactory   
    methods
        function res = factorymethod(~)
            res = object1();
        end
    end
end

methodfactory2.m

classdef methodfactory2 < methodfactory   
    methods
        function res = factorymethod(~)
            res = object2();
        end
    end
end

测试代码：

%工厂方法模式
fac1 = methodfactory1();
fac1.dosomething();
fac2 = methodfactory2();
fac2.dosomething();

抽象工厂模式：

ifactory.m

classdef ifactory
    methods(abstract)
        createobject(~);
    end
end

obj1factory.m

classdef obj1factory < ifactory
    methods
        function res = createobject(~)
            res = object1();
        end
    end
end

obj2factory.m

classdef obj2factory < ifactory
    methods
        function res = createobject(~)
            res = object2();
        end
    end
end

测试代码

fac1 = obj1factory();
obj1 = fac1.createobject();
obj1.desc();
 
fac2 = obj2factory();
obj2 = fac2.createobject();
obj2.desc();